The United boss said after the penultimate match of the tour against Liverpool that “he should be here, and he is not here”, then admitted on Tuesday that he did not know when the 22-year-old would be back with the group in Manchester.

Martial broke his silence shortly after the team landed back in the UK to confirm he will be back on Thursday, when there may well be a frosty reception despite the public justification of his absence.

“Thanks for all your posts,” he wrote on Twitter.

“My little Swan is fine, for the mum it was harder but thank god she is better now.

“Sorry but my family will always come first… back tomorrow in Manchester.”

Martial could reportedly be handed a two-week fine of around £180,000 for failing to return to America and Mourinho appeared to aim a thinly-veiled dig at him after beating Real as next Friday’s Premier League opener against Leicester looms large.

“My players, amazing in their effort but we have more effort in front of us,” said Mourinho, who leads United to Bayern Munich on Sunday in their final pre-season friendly.

“Because in a few days we go to Munich and we start the Premier League in nine days.

“These are the players that we have plus (Victor) Lindelof, that starts training two days ago, plus Marcus Rashford, (Phil) Jones and (Romelu) Lukaku because they gave to the group and to the team three days of their holidays.

“So, they’re coming back three days early to try and be available for the team.

Jose Mourinho has been unhappy about Martial´s absence (Adam Davy/PA)

“And with the fantastic spirit we have in the majority of the players, I repeat: in the majority of the players, we have a fantastic spirit, we go with everything we have to the Premier League.”

It is hard to see a thawing of the tensions between Martial and Mourinho, with the United forward sure to be one of the main subjects of transfer talk this month.

Full-back Matteo Darmian is another hoping to leave Old Trafford in the coming weeks, while Mourinho is hopeful of bringing in at least one of the two transfer targets he wants.

Brazil international Fred, young full-back Diogo Dalot and third-choice goalkeeper Lee Grant are all that have arrived so far this summer, but January acquisition Alexis Sanchez is now beginning to show his true quality.

“We were just trying to survive and to have the best possible results,” Mourinho said of the American tour. “But as I was saying to the players, some of my players they will be an amazing condition.

“You imagine an Alexis Sanchez fresh? The way the man is running after playing four matches of 90 minutes, I think he’s in a fantastic condition.

“So, let’s look at it from a positive side and wait for Lindelof, Rashford, Lukaku and Jones, which are going to be four important players for us.

“Not prepared but they will be back and when you are in trouble they will help us and that’s the spirit we need because I think our first two-three weeks in the Premier League – Leicester, Brighton, Tottenham – are going to be really hard for us because we didn’t prepare for that but that’s what it is.”